In obese children, low antioxidant vitamin intake and reduced antioxidant capacity are common. Weight reduction reduces subclinical inflammation in obese subjects, and, similarly, antioxidant vitamins have been shown to reduce the expression of proinflammatory cytokines. Moreover, antioxidants reduce oxidative stress which influences endothelial function and might play a crucial role in the pathogenesis of obesity-related disorders. Furthermore, overweight children and adults have a markedly increased risk for iron deficiency. The mechanism linking obesity with iron deficiency is unclear. Growing evidence suggests that the elevated inflammatory status associated with obesity increases circulating hepcidin and this contributes to iron deficiency. Weight reduction has been shown to be associated with reduced inflammation and serum hepcidin concentrations, and an improved functional iron state. Thus, reducing inflammation in obese children may improve iron metabolism and reduce their risk of iron deficiency.